Regeneron Begins Clinical Trials of Anti-Viral Antibody Cocktail

Regeneron Pharmaceuticals, Inc. has initiated the first clinical trial of REGN-COV2, its investigational dual antibody cocktail for the prevention and treatment of COVID-19. The REGN-COV2 clinical program will consist of four separate study populations:

• Hospitalized COVID-19 patients

• Non-hospitalized symptomatic COVID-19 patients

• Uninfected people in groups that are at high-risk of exposure (such as healthcare workers or first responders)

• Uninfected people with close exposure to a COVID-19 patient (such as the patient's housemate).

The placebo-controlled trials will be conducted at multiple sites.

"We have created a unique anti-viral antibody cocktail with the potential both to prevent and treat infection, and also to preempt viral 'escape,' a critical precaution in the midst of an ongoing global pandemic," said George D. Yancopoulos, M.D., Ph.D., co-founder, president and chief scientific officer of Regeneron. "REGN-COV2 could have a major impact on public health by slowing spread of the virus and providing a needed treatment for those already sick – and could be available much sooner than a vaccine. The antibody cocktail approach may also have long-term utility for elderly and immuno-compromised patients, who often do not respond well to vaccines. Ultimately, the world needs multiple solutions for COVID-19, and the innovative biopharma industry is collectively working hard to help as many people as possible with a variety of complementary approaches."

Evaluating the Antibodies

Regeneron scientists evaluated thousands of fully-human antibodies produced by the company's proprietary VelocImmune mice, which have been genetically-modified to have a human immune system, as well as antibodies isolated from humans who have recovered from COVID-19. They selected the two most potent, non-competing and virus-neutralizing antibodies and have scaled them up for clinical use with the company's in-house VelociMab and manufacturing capabilities. The two antibodies bind non-competitively to the critical receptor binding domain (RBD) of the virus's spike protein, which diminishes the ability of mutant viruses to escape treatment, as demonstrated in upcoming Science publications of preclinical research.

REGN-COV2's preclinical development and preclinical/clinical manufacturing has been funded in part with federal funds from the Biomedical Advanced Research and Development Authority (BARDA), part of the office of the Assistant Secretary for Preparedness and Response at the U.S. Department of Health and Human Services.

The first two adaptive Phase 1/2/3 studies are evaluating REGN-COV2 (REGN10933+REGN10987) as a treatment for hospitalized and non-hospitalized patients with COVID-19. The Phase 1 portion will focus on virologic and safety endpoints, and the Phase 2 portion will focus on virologic and clinical endpoints. Data from the Phase 1 and Phase 2 studies will be used to refine the endpoints and determine size for the Phase 3 studies.

"We are particularly excited to begin studies of REGN-COV2, which is a novel antibody cocktail targeted specifically against SARS-CoV-2," said trial investigator Dr. Suraj Saggar, chief of infectious disease at Holy Name Medical Center in Teaneck, New Jersey. "Over the last long months, we have learned that repurposing existing medicines unfortunately does not offer a broadly effective solution for COVID-19. For this reason, we need to investigate custom-designed approaches like REGN-COV2. The first studies will evaluate if REGN-COV2 can improve disease outcomes in both hospitalized and non-hospitalized patients with COVID-19."